Various antenna types are known for use in handheld communication devices.
In a Radio Frequency (RF) simulation, an antenna can be represented as an antenna model to evaluate RF coverage. The antenna model describes how the antenna radiates RF energy.
In current practices, RF simulation tools use one-dimensional (1-D) antenna models or three dimensional (3-D) models, and are generally sufficient for evaluating RF coverage on a macro cellular scale. For example, a one-dimensional or 3-D antenna pattern is usually adequate to model RF coverage of a large cellular tower that is physically located in an open environment.
Recently, however, with the implementation of micro-cellular infrastructures in Wireless Local Area Networks (WLANS), the antenna may be small and physically located in a closed environment, which affects RF coverage. The microcellular antennas may be within the proximity of wall structures or embedded in environments, such as a vehicle, having complex surfaces. In these environments, a one-dimensional antenna pattern is insufficient to predict RF coverage.
As is known, antenna design is based on at least three major parameters, namely: return loss, efficiency and radiation pattern. In most RF planning tools the radiation pattern which is usually 1-D, consists of one cut of the vertical plane, digitized and then used in the RF planning tool as the radiated energy at one plane only. Although some RF planning tools have introduced 3-D radiation patterns, these patterns lack the ability to incorporate effects of nearby scattering structures. Consequently, the RF planning tools can produce inaccurate simulations, and system deployment based on such RF planning tools can lead to unpredictable results.